Antiviral Drugs (excluding HIV drugs) Flashcards
Mechanism: Sofosbuvir
Inhibits HCV RNA-dependent RNA polymerase acting as a chain terminator
Mechanism: Simeprevir
HCV protease inhibitor → prevents viral replication
When using Cidofovir, coadminister ___ and ___ to decrease nephrotoxicity
Probenecid
IV saline
Clinical use: Ribavirin
- Chronic HCV
- RSV (Palivizumab preferred in children)
Clinical use:
Oseltamivir
Zanamivir
Treatment and prevention of both influenza A and B
Beginning therapy within 48 hours of symptom onset may shorten duration of illness
Clinical use:
Acyclovir
Famciclovir
Valacyclovir
HSV - mucocutaneous/genital lesions, encephalitis
VZV - reduce symptoms of chickenpox (early)
Weak activity against EBV
No activity against CMV (no thymidine kinase)
VZV prophylaxis in immunocompromised patients
No effect on latent forms of HSV and VZV
Valcyclovir is a prodrug of Acyclovir (better oral F)
Herpes zoster → Famciclovir
Mechanism: Cidofovir
Preferentially inhibits viral DNA polymerase
Does not require phosphorylation by viral kinase
Long T1/2
Adverse effects: Cidofovir
- Nephrotoxicity (coadminister with Probenecid and IV saline to decrease toxicity)
Mechanism: Foscarnet
Inhibition:
- Viral DNA/RNA polymerase
- HIV reverse transcriptase
Binds pyrophosphate-binding site of enzyme
Does not require kinase activation
Clinical use: Simeprevir
Chronic HCV in combination with Ledipasvir (NS5A inhibitor)
NOT used as monotherapy
Adverse effects: Foscarnet
- Nephrotoxicity
- Electrolyte abnormalities → can lead to seizures
- Hypo- or hypercalcemia
- Hypo- or hyperphosphatemia
- Hypokalemia
- Hypomagnesemia
Clinical use: Sofosbuvir
Chronic HCV in combination with:
- Ribavirin
- Simeprevir
- Ledipasvir (NS5A inhibitor)
- +/- Peginterferon alfa
NOT used as monotherapy
Adverse effects: Ganciclovir
-
Bone marrow suppression
(leukopenia, neutropenia, thrombocytopenia) - Renal toxicity
- More toxic to host enzymes than Acyclovir
Mechanism: Ribavirin
Inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase
Also inhibits other mechanisms involved in viral replication
Clinical use: Ganciclovir
CMV, especially in immunocompromised patients
Valganciclovir - prodrug of ganciclovir with better oral bioavailability